Radio frequency system for wearable device

ABSTRACT

A radio frequency (RF) system includes an RF integrated circuit (IC) die, and an antenna coupled to the RF IC die. The RF system further includes a reflector layer over the RF IC die, the reflector layer extending over at least a portion of the antenna, a combination of the antenna and the reflector layer having a radiation pattern that comprises a main lobe in a first direction parallel to a top surface of the reflector layer.

TECHNICAL FIELD

The present disclosure relates generally to an electronic device, andmore particularly to a radio frequency (RF) system with an RF integratedcircuit (RFIC) and an antenna system to be utilized in a wearabledevice.

BACKGROUND

Applications in the millimeter-wave frequency regime have gainedsignificant interest in the past few years due to the rapid advancementin low cost semiconductor technologies such as silicon germanium (SiGe)and fine geometry complementary metal-oxide semiconductor (CMOS)processes. Availability of high-speed bipolar and metal-oxidesemiconductor (MOS) transistors has led to a growing demand forintegrated circuits for mm-wave applications at 60 GHz, 77 GHz, and 80GHz, and also beyond 100 GHz. Such applications include, for example,automotive radar systems, multi-gigabit communication systems, andwearable consumer devices such as smart watches, activity monitors andhealth monitors.

In some radar systems, the distance between the radar and a target isdetermined by transmitting a frequency modulated signal, receiving areflection of the frequency modulated signal, and determining a distancebased on a time delay and/or frequency difference between thetransmission and reception of the frequency modulated signal.Accordingly, some radar systems include a transmit antenna to transmitthe RF signal, a receive antenna to receive the RF, as well as theassociated RF circuitry used to generate the transmitted signal and toreceive the RF signal. In some cases, multiple antennas may be used toimplement directional beams using phased array techniques.

SUMMARY

According to an embodiment, a radio frequency (RF) system includes an RFintegrated circuit (IC) die, and an antenna coupled to the RF IC die.The RF system further includes a reflector layer over the RF IC die, thereflector layer extending over at least a portion of the antenna, acombination of the antenna and the reflector layer having a radiationpattern that comprises a main lobe in a first direction parallel to atop surface of the reflector layer.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings, in which:

FIG. 1A illustrates a perspective view of an RF circuitry/antennapackage mounted on a circuit board in accordance with some embodiments;

FIG. 1B illustrates a perspective view of an RF circuitry/antennapackage mounted on a circuit board with a corresponding radiationpattern in accordance with some embodiments;

FIG. 2 illustrates a schematic diagram of a mm-wave gesture sensingsystem in accordance with some embodiments;

FIG. 3A illustrates a top view of a wearable device in accordance withsome embodiments;

FIG. 3B illustrates a cross-sectional view of a wearable device inaccordance with some embodiments;

FIG. 4A illustrates a perspective view of an RF circuitry/antennapackage mounted on a circuit board in accordance with some embodiments;

FIG. 4B illustrates a three-dimensional plot showing a radiation patternof an RF circuitry/antenna package in accordance with some embodiments;

FIG. 4C illustrates a perspective view of an RF circuitry/antennapackage mounted on a circuit board with a corresponding radiationpattern in accordance with some embodiments;

FIG. 5A illustrates a perspective view of an RF circuitry/antennapackage mounted on a circuit board in accordance with some embodiments;

FIG. 5B illustrates a three-dimensional plot showing a radiation patternof an RF circuitry/antenna package in accordance with some embodiments;

FIG. 5C illustrates a perspective view of an RF circuitry/antennapackage mounted on a circuit board with a corresponding radiationpattern in accordance with some embodiments;

FIG. 6A illustrates a top view of a wearable device in accordance withsome embodiments;

FIG. 6B illustrates a cross-sectional view of a wearable device inaccordance with some embodiments;

FIG. 6C illustrates a planar view of a wearable device in accordancewith some embodiments;

FIG. 7A illustrates a planar view of a wearable device in accordancewith some embodiments;

FIG. 7B illustrates a planar view of a wearable device in accordancewith some embodiments;

FIG. 7C illustrates a planar view of a wearable device in accordancewith some embodiments; and

FIG. 8 illustrates a flow diagram of a method of operating a gesturesensing system integrated into a wearable device in accordance with someembodiments.

Corresponding numerals and symbols in different figures generally referto corresponding parts unless otherwise indicated. The figures are drawnto clearly illustrate the relevant aspects of the preferred embodimentsand are not necessarily drawn to scale. To more clearly illustratecertain embodiments, a letter indicating variations of the samestructure, material, or process step may follow a figure number.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The making and using of the presently preferred embodiments arediscussed in detail below. It should be appreciated, however, that thepresent invention provides many applicable inventive concepts that canbe embodied in a wide variety of specific contexts. The specificembodiments discussed are merely illustrative of specific ways to makeand use the invention, and do not limit the scope of the invention.

The present disclosure will be described with respect to embodiments ina specific context, a radio frequency (RF) system including an RFintegrated circuit (RFIC) and an antenna system. In particular, variousembodiments below will be described with respect to an RF system that isa part of a gesture sensing system of a wearable consumer device suchas, for example, a smart watch. Various embodiments presented herein mayalso be applied to other systems and applications, such as otherwearable/portable consumer devices (such as health monitoring systems,activity monitoring systems, mobile phones, tablet devices, portablegaming consoles, photo cameras, video camcorders, laptop computers,notebook computers, or the like) and non-portable consumer devices (TVsets, gaming consoles, desktop computers, or the like).

In various embodiments presented herein, an RF system is provided, whichmay be integrated into a gesture sensing system of a wearable device. Invarious embodiments, the gesture sensing system may be implemented usingmm-wave RF circuits to produce a mm-wave gesture sensing system. In anembodiment, the gesture sensing system includes an RF system, includingRF circuitry and antennas, which is implemented in a ball grid array(BGA) package. Such an RF circuitry/antenna package includes anintegrated circuit having a receive interface on a first edge of chipand transmit interfaces on adjacent or opposite edges of the chip. Amulti-element patch antenna is disposed on a surface of the packageadjacent to the first edge of the chip, and is coupled to multiplereceive channel interfaces at the first edge of the chip. Similarly,patch antennas for transmitting signals are disposed on theredistribution layer of the package on the adjacent or opposite edges ofthe chip adjacent to the transmit interfaces.

In some embodiments, beam forming concepts, which are widely used inradar systems, may be used to impart beam steering and directionality tothe transmission and reception of RF signals. Such embodiments may beapplied, for example, to automotive radar systems, camera systems,portable systems, wearable systems, TV sets, tablet computers, and otherapplications. Embodiment beam forming concepts may also be used toimplement a gesture recognition system. In the past, gesture recognitionsystems have been implemented using optical cameras, pressure sensors,PALs and other devices. By using embodiment radar systems, a gesturerecognition system may perform accurate distance measurements, whilebeing conveniently hidden behind an opaque cover made of plastic orother sturdy materials.

In some embodiments, a gesture sensing system is integrated on a circuitboard of a wearable device such as, for example, a smart watch. In anembodiment, an antenna of an RF circuitry/antenna package of the gesturesensing system is formed to have a radiation pattern such that theantenna transmits or receives RF signals in a direction that is notblocked by other components of a wearable device, such as a display ofthe wearable device. In another embodiment, an RF circuitry/antennapackage of the gesture sensing system includes a reflector layer tomodify a radiation pattern of an antenna of the RF circuitry/antennapackage. The reflector layer reflects and/or suppressestransmission/reception of RF signals in undesired directions (such as,for example, a direction toward a display of a wearable device) andredirects the radiation energy to desired directions (such as, forexample, a direction parallel to a display of a wearable device). Insuch embodiments, portions of a housing of the wearable device may beformed of a suitable material that is transparent for mm-wave RFsignals.

FIG. 1A illustrates a perspective view of an RF circuitry/antennapackage 103 mounted on a circuit board 101 in accordance with someembodiments. In an embodiment, the RF circuitry/antenna package 103 ismounted on the circuit board 101 using solder balls (not shown). Thecircuit board 101 may be implemented using an insulating substratehaving one or more thin conductive layers (not individually shown)laminated on one or both sides of the insulating substrate. The one ormore thin conductive layers are patterned (for example, etched) to formcircuitry interconnections of the circuit board 101. The one or morethin conductive layers may be configured as ground, power and/or signallayers. In an embodiment, the insulating substrate is formed of FR4 andthe one or more thin conductive layers are formed of copper.Alternatively, other insulating materials, such as Rogers PCB material,or conductive materials may be used form the circuit board 101. In someembodiments, the circuit board 101 may include additional conductive andinsulating layers as known in the art.

In an embodiment, the RF circuitry/antenna package 103 includes an RFfront-end integrated circuit (IC) die 105, transmit antennas 107 a and107 b, and receive antennas 109 a-109 d. The RF circuitry/antennapackage 103 is configured to transmit an incident RF signal toward anobject (such as, for example, a hand of a consumer when the RFcircuitry/antenna package 103 is a part of a gesture sensing system of awearable device) via transmit antennas 107 a and 107 b, and receive areflected RF signal from the object via receive antennas 109 a-109 d.The RF front-end IC die 105 includes a receiver front end (not shown)coupled to the receive antennas 109 a-109 d and a transmitter front end(not shown) coupled to the transmit antennas 107 a and 107 b. In anembodiment, the transmit antennas 107 a and 107 b and the receiveantennas 109 a-109 d are implemented using patch antennas. As describedbelow in greater detail, the transmit antennas 107 a and 107 b and thereceive antennas 109 a-109 d may be implemented using other type ofantennas based on design requirements for the RF circuitry/antennapackage 103. The RF front-end IC die 105 provides signals to betransmitted to the transmitter front end and receives and/or processessignals received by the receiver front end. In some embodiments, thefrequency of operation of the RF circuitry/antenna package 103 isbetween about 57 GHz and about 66 GHz. Alternatively, embodiment systemsmay operate at frequencies outside of this range also.

As shown, the RF circuitry/antenna package 103 is an embedded waferlevel (eWLB) ball grid array (BGA) package that includes a moldingmaterial layer. In such an embodiment, the RF front-end IC die 105 isdisposed within the molding material layer. The RF circuitry/antennapackage 103 may further include conductive layers, such asredistribution layers (RDLs), used for routing and/or for theimplementation of various passive and/or active devices within thepackage. The transmit antennas 107 a and 107 b, and the receive antennas109 a-109 d may be implemented using the RDLs. Alternatively, otherpackage types such as a BGA package or advanced thin small leadless(ATSPL) package may also be used to implement the RF circuitry/antennapackage 103.

FIG. 1B illustrates a perspective view of the RF circuitry/antennapackage 103 mounted on the circuit board 101 with a correspondingradiation pattern 111 of the receive antennas 109 a-109 d in accordancewith some embodiments. In an embodiment where the receive antennas 109a-109 d are implemented using patch antennas, the radiation pattern 111of the receive antennas 109 a-109 d has a “half-ball” shape disposed ona top surface of the RF circuitry/antenna package 103 above the receiveantennas 109 a-109 d. The receive antennas 109 a-109 d are configured toreceive RF signals from directions according the radiation pattern 111.Accordingly, an obstacle placed above the top surface of the RFcircuitry/antenna package 103 may adversely affect the performance ofthe RF circuitry/antenna package 103 by blocking most sensitive (havinghighest gain) directions of the receive antennas 109 a-109 d.

FIG. 2 illustrates a schematic diagram of a mm-wave gesture sensingsystem 200 in accordance with some embodiments. As shown, a radartransceiver device 201 is configured to transmit an incident RF signaltoward a gesturing hand 217 via transmit antenna 213 a and/or transmitantenna 213 b, and receive a reflected RF signal via an antenna arraythat includes receive antennas 215 a-215 d. The radar transceiver device201 includes a receiver front end 211 coupled to the receive antennas215 a-215 d, a first transmitter front end 203 coupled to the transmitantenna 213 a and a second transmitter front end 209 coupled to thetransmit antenna 213 b. Radar circuitry 205 provides signals to betransmitted to the first and second transmitter front ends 203 and 209,and receives signals via the receiver front end 211. Processingcircuitry 207 processes the received signals, as well as controls thetransmissions produced by the first transmitter front end 203 and thesecond transmitter front end 209. In some embodiments, the mm-wavegesture sensing system 200 is implemented as a frequency modulatedcontinuous wave (FMCW) radar sensor having two transmit channels andfour receive channels to realize a digital beam forming holographicradar such that a relative speed, distance, and phase of each target inthe field of view (FOV) in front of the antennas is measured. In otherembodiments, the number of transmit channels and the number of receivechannels may vary according to design requirements for the mm-wavegesture sensing system 200.

During operation, position and gestures of a gesturing hand 217 may bedetected by the radar transceiver device 201 and/or other processingcircuitry coupled thereto. For example, the radar transceiver device 201may be coupled to a wearable device, a computer system, an appliance, orother devices, and the detected gestures may be used as an input to suchdevices. For example, a gesture of two fingers tapping each other couldbe interpreted as a “button press,” or a gesture of a rotating thumb andfinger may be interpreted as a turning a dial.

In some embodiments, the radar transceiver device 201, or portions ofthe radar transceiver device 201 may be implemented in a package (suchas the the RF circuitry/antenna package 103 described above withreference to FIG. 1A) that contains radar circuitry 205, the firsttransmitter front end 203, the second transmitter front end 209, thereceiver front end 211, as well as the transmit antennas 213 a and 213b, and the receive antennas 215 a-215 d. In other embodiments, the radartransceiver device 201 may be implemented as one or more integratedcircuits disposed on a circuit board, and the transmit antennas 213 aand 213 b and the receive antennas 215 a-215 d may be implemented on thecircuit board adjacent to the integrated circuits. Various methods ofoperation of a gesture sensing system (such as the mm-wave gesturesensing system 200) have been described in U.S. application Ser. No.14/954,198, filed on Nov. 30, 2015, which application is herebyincorporated herein by reference in its entirety.

FIGS. 3A and 3B illustrate top and cross-sectional views, respectively,of a wearable device 300 in accordance with some embodiments. In theillustrated embodiment, the wearable device 300 is a smart watch.Alternatively, the wearable device 300 may be a health monitoringsystem, an activity monitoring system, or like. The wearable device 300includes a housing 301, which houses various components of the wearabledevice 300, acts as a mechanical support and provides protection tovarious components of the wearable device 300. The housing 301 may beformed using any suitable material providing desired support andprotection to various components of the wearable device 300. Forexample, the housing 301 may be formed using metals, metal alloys, orthe like. The wearable device 300 further includes a band 303 attachedto the housing 301 and configured to attach the wearable device 300 to awrist of a consumer, for example. The band 303 is not illustrated inFIG. 3B, since FIG. 3B shows a cross-sectional view in the YZ plane.

The wearable device 300 further includes a circuit board 305, whichelectrically couples various electrical components or devices mounted onthe circuit board 305. The circuit board 305 may be formed using similarmaterials and methods as the circuit board 101 described above withreference to FIG. 1A, and the description is not repeated herein for thesake of brevity. In an embodiment, an RF circuitry/antenna package 307and various electrical components (represented by two electricalcomponents 309 and 311 in FIG. 3B) are mounted on the circuit board 305to form a gesture sensing system (such as, for example, the mm-wavegesture sensing system 200 described above with reference to FIG. 2).The RF circuitry/antenna package 307 may be similar to the RFcircuitry/antenna package 103 described above with reference to FIG. 1A,and the description is not repeated herein for the sake of brevity. Theelectrical components 309 and 311 may include a crystal oscillator(Xtal), a phase locked loop (PLL) circuit, baseband amplifiers,analog-to-digital converters (ADCs), switches, a power managementintegrated circuit (PMIC), or the like.

As shown, the wearable device 300 further includes a display 313 coupledto the circuit board 305. The display 313 covers the circuit board 305and various electrical components or devices mounted on the circuitboard 305, such as the RF circuitry/antenna package 307. The display 313may be an LCD, an LED display, an AMOLED display, or the like. One ofordinary skill in the art will appreciate that the circuit board 305 mayfurther include additional components (not shown) depending onfunctional requirement of the wearable device 300. In some embodiments,the circuit board 305 may include various application specificintegrated circuits (ASICs), various components for powering andcontrolling the display 313, various sensors, such as a motion sensor, apressure sensor, a temperature sensor, a humidity sensor, a touchsensor, a heart rate sensor, or the like, various interface components,such as USB, WiFi, WiGig, Bluetooth, or the like, various powermanagement components, and a power source, such as a battery, or thelike.

In an embodiment, receive antennas of the RF circuitry/antenna package307 have a radiation pattern similar to the radiation pattern 111illustrated in FIG. 1B. Accordingly, the receive antennas of the RFcircuitry/antenna package 307 have a highest gain predominantly in the Zdirection. In such embodiments, mm-wave RF signals 315 received by theRF circuitry/antenna package 307 are blocked by the display 313 or a topportion of the housing 301, since the display 313 or the top portion ofthe housing 301 are formed of materials that are not transparent formm-wave RF signals. In an embodiment, the display 313 of the wearabledevice 300 is reshaped, such that the reshaped display 313 does notblock the RF signals 315 of the RF circuitry/antenna package 307.Alternatively, the RF circuitry/antenna package 307 is placed in alocation of the wearable device 300 (such as, for example, a junction ofthe housing 301 and the band 303 of the wearable device 300) that is notobstructed by the display 313.

As described below in greater detail, in other embodiments, an RFcircuitry/antenna package may be configured such that antennas of the RFcircuitry/antenna package have a highest gain predominantly in the Ydirection. In such embodiments, a portion or an entire sidewall of thehousing 301 is formed of a material that is transparent for mm-wave RFsignals to ensure proper operation of a gesture sensing system of awearable device.

FIG. 4A illustrates a perspective view of a portion of an RFcircuitry/antenna package 403 mounted on a circuit board 401 inaccordance with some embodiments. The circuit board 401 may be formedusing similar materials and methods as the circuit board 101 describedabove with reference to FIG. 1A, and the description is not repeatedherein for the sake of brevity. As shown, the RF circuitry/antennapackage 403 includes an RF front-end IC die 405 coupled to a receiveantenna 407, which is implemented using a Yagi-Uda antenna with aradiation pattern having a main lobe in the Y direction (see FIG. 4B).In other embodiments, other directional antennas, such as a Vivaldiantenna, a bow-tie antenna, or the like, may be used to implement thereceive antenna 407.

FIG. 4B illustrates a three-dimensional plot showing a radiation pattern409 of the RF circuitry/antenna package 403, where the receive antenna407 is implemented using a Yagi-Uda antenna. Compared to the radiationpattern 111 illustrated in FIG. 1B, the radiation pattern 409 shows apronounced directionality in the Y direction. In an embodiment, theradiation pattern 409 has a main lobe 4 o 9 m in the Y direction.Furthermore, the radiation pattern 409 has a side lobe 409 s in the Zdirection, with the side lobe 409 s having a similar gain as the mainlobe 409 m.

FIG. 4C illustrates a perspective view of the RF circuitry/antennapackage 403 mounted on the circuit board 401 with the correspondingradiation pattern 409 in accordance with some embodiments. Inparticular, FIG. 4C illustrates a location of the radiation pattern 409with respect to the receive antenna 407 and other components of the RFcircuitry/antenna package 403. As described below in greater detail, themain lobe 409 m of the radiation pattern 409 may be increased bysuppressing the side lobe 409 s of the radiation pattern 409 using areflector layer placed on top of the RF circuitry/antenna package (seeFIGS. 5A, 5B and 5C).

FIG. 5A illustrates a perspective view of a portion of an RFcircuitry/antenna package 503 mounted on a circuit board 501 inaccordance with some embodiments. The circuit board 501 may be formedusing similar materials and methods as the circuit board 101 describedabove with reference to FIG. 1A, and the description is not repeatedherein for the sake of brevity. In an embodiment, the RFcircuitry/antenna package 503 includes an RF front-end IC die 505coupled to a receive antenna 507, which is implemented using a Yagi-Udaantenna with a radiation pattern having a main lobe in the Y direction(see FIG. 5B). In other embodiments, other directional antennas, such asa Vivaldi antenna, a bow-tie antenna, or the like, may be used toimplement the receive antenna 507.

Referring further to FIG. 5A, a reflector layer 509 is formed over a topsurface of the RF circuitry/antenna package 503 such that reflectorlayer 509 is formed over the RF front-end IC die 505 and at leastpartially over the receive antenna 507. The reflector layer 509 may beformed of a metallic material, such as aluminum, silver, copper, alloysthereof, or the like. As shown, the reflector layer 509 is formed overthe RF circuitry/antenna package 503 after forming the RFcircuitry/antenna package 503. In such an embodiment, the reflectorlayer 509 may be attached to the top surface of the RF circuitry/antennapackage 503 using a suitable adhesive. Subsequently, the RFcircuitry/antenna package 503 with the attached reflector layer 509 maybe mounted on the circuit board 501. In another embodiment, thereflector layer 509 is formed over the RF circuitry/antenna package 503after mounting the RF circuitry/antenna package 503 on the circuit board501.

In yet another embodiment, the reflector layer 509 may be attached tothe RF front-end IC die 505 during a packaging process to form the RFcircuitry/antenna package 503. In such an embodiment, the reflectorlayer 509 may be a liquid metal pad and may be attached to the topsurface of the RF front-end IC die 505 before encapsulating the RFfront-end IC die 505. After attaching the reflector layer 509 to the topsurface of the RF front-end IC die 505, the reflector layer 509 and theRF front-end IC die 405 may be encapsulated in a molding material toform the RF circuitry/antenna package 503.

FIG. 5B illustrates a three-dimensional plot showing a radiation pattern511 of the RF circuitry/antenna package 503, where the receive antenna507 is implemented using a Yagi-Uda antenna, and where the reflectorlayer 509 is formed over the RF front-end IC die 505 and the receiveantenna 507 of the RF circuitry/antenna package 503. In an embodiment,the radiation pattern 511 has a main lobe 511 m and side lobes 511 s,with the main lobe 511 m being in the Y direction and the side lobes 511s being in the XZ plane. Compared to the radiation pattern 409illustrated in FIG. 4B, the side lobes 511 s of the radiation pattern511 are smaller than the side lobe 409 s of the radiation pattern 409.In an embodiment, the reflector layer 509 reflects the RF energy in theside lobes 511 s and redirects the RF energy to the main lobe 511 m.Accordingly, the main lobe 511 m is pronounced, while the side lobes 511s are suppressed.

FIG. 5C illustrates a perspective view of the RF circuitry/antennapackage 503 mounted on the circuit board 501 with the correspondingradiation pattern 511 in accordance with some embodiments. Inparticular, FIG. 5C illustrates a location of the radiation pattern 511with respect to the receive antenna 507, the reflector layer 509, andother components of the RF circuitry/antenna package 503.

FIGS. 6A and 6B illustrate top and cross-sectional views, respectively,of a wearable device 600 in accordance with some embodiments. In theillustrated embodiment, the wearable device 600 is a smart watch.Alternatively, the wearable device 600 may be a health monitoringsystem, an activity monitoring system, or like. The wearable device 600includes a housing 601, which houses various components of the wearabledevice 600, acts as a mechanical support and provides protection tovarious components of the wearable device 600. In an embodiment, thehousing 601 includes a top portion 601 t, a bottom portion 601 b, andsidewalls 601 s separating the top portion 601 t from the bottom portion601 b. The top portion 601 t and the bottom portion 601 b of the housing601 may be formed of metals, metal alloys, or the like. In anembodiment, at least a portion of the sidewalls 601 s of the housing 601may be formed of a suitable material that is transparent for mm-wave RFsignals. The wearable device 600 further includes a band 603 attached tothe housing 601 and configured to attach the wearable device 600 to awrist of a consumer, for example. The band 603 is not illustrated inFIG. 6B, since FIG. 6B shows a cross-sectional view in the YZ plane.

The wearable device 600 further includes a circuit board 605, whichelectrically couples various electrical components or devices mounted onthe circuit board 605. The circuit board 605 may be formed using similarmaterials and methods as the circuit board 101 described above withreference to FIG. 1A, and the description is not repeated herein for thesake of brevity. In an embodiment, the RF circuitry/antenna package 607and various electrical components (represented by two electricalcomponents 609 and 611 in FIG. 6B) are mounted on the circuit board 605to form a gesture sensing system (such as the mm-wave gesture systemdescribed above with reference to FIG. 2). The RF circuitry/antennapackage 607 may be implemented using the RF circuitry/antenna package403 described above with reference to FIG. 4A, or the RFcircuitry/antenna package 503 described above with reference to FIG. 5A.The electrical components 609 and 611 may include a crystal oscillator(Xtal), a phase locked loop (PLL) circuit, baseband amplifiers,analog-to-digital converters (ADCs), switches, a power managementintegrated circuit (PMIC), or the like.

The wearable device 600 further includes a display 613 coupled to thecircuit board 605. The display 613 covers the circuit board 605 andvarious electrical components mounted to the circuit board 605, such asthe RF circuitry/antenna package 607. The display 613 may be an LCD, anLED display, an AMOLED display, or the like. One of ordinary skill inthe art will appreciate that the circuit board 605 may includeadditional components (not shown) depending on functional requirement ofthe wearable device 600. In some embodiments, the circuit board 605 mayfurther include various application specific integrated circuits(ASICs), various components for powering and controlling the display613, various sensors, such as a motion sensor, a pressure sensor, atemperature sensor, a humidity sensor, a touch sensor, a heart ratesensor, or the like, various interface components, such as USB, WiFi,WiGig, Bluetooth, or the like, various power management components, anda power source, such as a battery, or the like.

Referring further to FIG. 6B, in an embodiment where the RFcircuitry/antenna package 607 is implemented using the RFcircuitry/antenna package 403 (see FIG. 4A), the RF circuitry/antennapackage 607 has a radiation pattern similar to the radiation pattern 409illustrated in FIG. 4B. In another embodiment where the RFcircuitry/antenna package 607 is implemented using the RFcircuitry/antenna package 503 (see FIG. 5A), the RF circuitry/antennapackage 607 has a radiation pattern similar to the radiation pattern 511illustrated in FIG. 5B. Accordingly, the RF circuitry/antenna package607 has a highest gain predominantly in the Y direction. In suchembodiments, mm-wave RF signals 516 transmitted or received by the RFcircuitry/antenna package 607 pass though the sidewall 601 s of thehousing 601 and are not blocked by the display 613 or the top portion601 t of the housing 601. Accordingly, the display 613 of the wearabledevice 600 may not be reshaped to expose the RF circuitry/antennapackage 607.

Referring further to FIG. 6B, in an embodiment where the RFcircuitry/antenna package 607 is implemented using the RFcircuitry/antenna package 503 (see FIG. 5A), the reflector layer 509 maybe configured to act as a heat sink. In such embodiments, the reflectorlayer 509 may be formed of a high thermal conductivity material (such asa metallic material), may be coupled to the top portion 601 t of thehousing 601, and may be configured to transfer heat generated in the RFfront-end IC die 505 to the top portion 601 t of the housing 601 to befurther dissipated into the environment. Furthermore, the bottom portion601 b of the housing 601, which is in contact with skin of a consumerwhile worn, may be formed of a low thermal conductivity material toavoid discomfort or bodily harm to the skin of the consumer.

FIG. 6C illustrates a planar view of the wearable device 600 notobscured by the display 613. In particular, FIG. 6C shows a location ofthe RF circuitry/antenna package 607 with respect to other components ofthe wearable device 600. During operation of the mm-wave gesture sensingsystem of the wearable device 600, the RF signals 615 that aretransmitted to and reflected from a gesturing hand 617 pass through thesidewall 601 s of the housing 601 and are not blocked by the display 613(see FIGS. 6A and 6B) or the band 603 of the wearable device 600. In anembodiment, the RF signals 615 intersect with a portion of the sidewall601 s of the housing 601. In other words, high-gain directions of the RFcircuitry/antenna package 607, such as directions defined by a main lobeof a radiation pattern of the RF circuitry/antenna package 607 (see, forexample, the radiation patterns 409 and 511 in FIGS. 4B and 5B,respectively), intersect a portion of the sidewall 601 s of the housing601. Accordingly, the portion of the sidewall 601 s of the housing 601intersecting with the RF signals 615 is formed of a material transparentfor the mm-wave RF signals. Remaining portion of the sidewall 601 s ofthe housing 601 may be formed of a material that is not transparent forthe mm-wave RF signals, such as a metallic material, for example. Inother embodiments, the entire sidewall 601 s of the housing 601 may beformed of a material transparent for the mm-wave RF signals.

FIGS. 7A, 7B and 7C illustrate planar views of wearable devices 700A,700B and 700C, respectively, where receive and transmit antennas areimplemented using a directional antenna, such as a Yagi-Uda antenna.Furthermore, FIGS. 7A, 7B and 7C show various antenna arrangements ofrespective RF circuitry/antenna packages of the wearable devices 700A,700B and 700C. In the illustrated embodiments, the wearable devices700A, 700B and 700C are smart watches. Alternatively, the wearabledevices 700A, 700B and 700C may be health monitoring systems, activitymonitoring systems, or like.

Referring to FIG. 7A, the wearable device 700A includes a housing 701,which houses various components of the wearable device 700A, acts as amechanical support and provides protection to various components of thewearable device 700A. In an embodiment, the housing 701 includes a topportion (not shown), a bottom portion (not shown), and a sidewall 701 sseparating the top portion from the bottom portion. The top portion andthe bottom portion of the housing 701 may be formed of metals, metalalloys, or the like. In an embodiment, at least a portion of thesidewalls 701 s of the housing 701 may be formed of a suitable materialthat is transparent for mm-wave RF signals. The wearable device 700Afurther includes a band 703 that is attached to the housing 701 and isconfigured to attach the wearable device 700A to a wrist of a consumer,for example.

The wearable device 700A further includes a circuit board 705, whichelectrically couples various electrical components or devices mounted onthe circuit board 705. The circuit board 705 may be formed using similarmaterials and methods as the circuit board 101 described above withreference to FIG. 1A, and the description is not repeated herein for thesake of brevity. In an embodiment, the RF circuitry/antenna package 707Aand various electrical components (not shown) are mounted on the circuitboard 705 to form a gesture sensing system (such as the mm-wave gesturesystem described above with reference to FIG. 2). The electricalcomponents may include a crystal oscillator (Xtal), a phase locked loop(PLL) circuit, baseband amplifiers, analog-to-digital converters (ADCs),switches, a power management integrated circuit (PMIC), or the like.

The RF circuitry/antenna package 707A may be similar to the RFcircuitry/antenna package 403 (see FIG. 4A), or similar to the RFcircuitry/antenna package 503 (see FIG. 5A). In an embodiment, the RFcircuitry/antenna package 707A includes an RF front-end IC die 709,transmit antennas 713 a and 713 b, and receive antennas 715 a-715 d. TheRF circuitry/antenna package 707A is configured to transmit incident RFsignals 717 toward a gesturing hand 721 via the transmit antennas 713 aand 713 b, and receive reflected RF signals 719 from the gesturing hand721 via the receive antennas 715 a-715 d. The RF front-end IC die 709includes a receiver front end (not shown) coupled to the receiveantennas 715 a-715 d, and a transmitter front end (not shown) coupled tothe transmit antennas 713 a and 713 b. In an embodiment, the transmitantennas 713 a and 713 b and the receive antennas 715 a-715 d areimplemented using Yagi-Uda antennas. In other embodiments, otherdirectional antennas, such as Vivaldi antennas, bow-tie antennas, or thelike, may be used to implement the transmit antennas 713 a and 713 b andthe receive antennas 715 a-715 d.

In an embodiment, a reflector layer 711 is formed over a top surface ofthe RF circuitry/antenna package 707A, such that reflector layer 711 isformed over the RF front-end IC die 709 and at least partially over thetransmit antennas 713 a and 713 b and the receive antennas 715 a-715 d.The reflector layer 711 may be formed using similar materials andmethods as the reflector layer 509 described above with reference toFIG. 5A, and the description is not repeated herein for the sake ofbrevity. In other embodiments, the reflector layer 711 may be omitted.In an embodiment where the reflector layer 711 is formed over the RFcircuitry/antenna package 707A, a radiation pattern of each of thetransmit antennas 713 a and 713 b, and the receive antennas 715 a-715 dmay be similar to the radiation pattern 511 (see FIG. 5B). In anotherembodiment where reflector layer 711 is not formed over the RFcircuitry/antenna package 707A, a radiation pattern of each of thetransmit antennas 713 a and 713 b, and the receive antennas 715 a-715 dmay be similar to the radiation pattern 409 (see FIG. 4B).

In an embodiment, the wearable device 700A further includes a display(not shown) disposed over and coupled to the circuit board 705. Thedisplay may be an LCD, an LED display, an AMOLED display, or the like.One of ordinary skill in the art will appreciate that the circuit board705 may include additional components (not shown) depending onfunctional requirement of the wearable device 700A. In some embodiments,the circuit board 705 may further include various application specificintegrated circuits (ASICs), various components for powering andcontrolling the display, various sensors, such as a motion sensor, apressure sensor, a temperature sensor, a humidity sensor, a touchsensor, a heart rate sensor, or the like, various interface components,such as USB, WiFi, WiGig, Bluetooth, or the like, various powermanagement components, and a power source, such as a battery, or thelike.

Referring further to FIG. 7A, during operation of the RFcircuitry/antenna package 707A of the wearable device 700A, the incidentRF signals 717 that are transmitted to and the reflected RF signals 719that are reflected from the gesturing hand 721 pass through the sidewall701 s of the housing 701 and are not blocked by the display or the band703 of the wearable device 700A. In an embodiment, the incident RFsignals 717 and the reflected RF signals 719 intersect with a portion ofthe sidewall 701 s of the housing 701. In other words, high-gaindirections of the RF circuitry/antenna package 707A, such as directionsdefined by main lobes of the radiation patterns of the RFcircuitry/antenna package 707A (see, for example, the radiation patterns409 and 511 in FIGS. 4B and 5B, respectively), intersect a portion ofthe sidewall 701 s of the housing 701. Accordingly, the portion of thesidewall 701 s of the housing 701 intersecting with the incident RFsignals 717 and the reflected RF signals 719 is formed of a materialthat is transparent for the mm-wave RF signals. Remaining portion of thesidewall 701 s of the housing 701 may be formed of a material that isnot transparent for the mm-wave RF signals, such as a metallic material,for example. In other embodiments, the entire sidewall 701 s of thehousing 701 may be formed of a material transparent for the mm-wave RFsignals.

Referring to FIG. 7B, the wearable device 700B is similar to thewearable device 700A described above with reference to FIG. 7A, and thedescription is not repeated herein for the sake of brevity. An RFcircuitry/antenna package 707B of the wearable device 700B differs fromthe RF circuitry/antenna package 707A of the wearable device 700A by anarrangement of the transmit antennas 713 a and 713 b, and the receiveantennas 715 a-715 d. Similar to the wearable device 700A, the incidentRF signals 717 and the reflected RF signals 719 of the wearable device700B intersect with a portion of the sidewall 701 s of the housing 701,which is formed of a material that is transparent for the mm-wave RFsignals. Furthermore, since the transmit antennas 713 a and 713 b, andthe receive antennas 715 a-715 d of the RF circuitry/antenna package707B have a different arrangement than the transmit antennas 713 a and713 b, and the receive antennas 715 a-715 d of the RF circuitry/antennapackage 707A, the portion of the sidewall 701 s of the wearable device700B that is transparent for the mm-wave RF signals is different fromthe portion of the sidewall 701 s of the wearable device 700A that istransparent for the mm-wave RF signals. The RF circuitry/antenna package707B of the wearable device 700B operates in a similar manner as the RFcircuitry/antenna package 707A of the wearable device 700A describedabove with reference to FIG. 7A, and the description is not repeatedherein for the sake of brevity.

Referring to FIG. 7C, the wearable device 700C is similar to thewearable devices 700A and 700B described above with reference to FIGS.7A and 7B, respectively, and the description is not repeated herein forthe sake of brevity. An RF circuitry/antenna package 707C of thewearable device 700C differs from the RF circuitry/antenna packages 707Aand 707B of the wearable devices 700A and 700B, respectively, by anarrangement of the transmit antennas 713 a and 713 b, and the receiveantennas 715 a-715 d. Similar to the wearable devices 700A and 700B, theincident RF signals 717 and the reflected RF signals 719 of the wearabledevice 700C intersect with a portion of the sidewall 701 s of thehousing 701, which is formed of a material that is transparent for themm-wave RF signals. Furthermore, since the transmit antennas 713 a and713 b, and the receive antennas 715 a-715 d of the RF circuitry/antennapackage 707C have a different arrangement than the transmit antennas 713a and 713 b, and the receive antennas 715 a-715 d of the RFcircuitry/antenna packages 707A and 707B, the portion of the sidewall701 s of the wearable device 700C that is transparent for the mm-wave RFsignals is different from the portions of the sidewalls 701 s of thewearable devices 700A and 700B that are transparent for the mm-wave RFsignals. In the illustrated embodiment, the portion of the sidewall 701s of the wearable device 700C that is transparent for the mm-wave RFsignals includes two disconnected portions, such that the disconnectedportions are located on opposite sides of the sidewall 701 s of thehousing 701 of the wearable device 700C. The RF circuitry/antennapackage 707C of the wearable device 700C operates in a similar manner asthe RF circuitry/antenna package 707A of the wearable device 700Adescribed above with reference to FIG. 7A, and the description is notrepeated herein for the sake of brevity.

FIG. 8 illustrates a flow diagram of a method 800 of operating a gesturesensing system integrated into a wearable device in accordance with someembodiments. The method 800 starts at step 801, where an RF system (suchas, for example, the RF circuitry/antenna packages 707A, 707B and 707Cillustrated in FIGS. 7A, 7B and 7C, respectively) of the gesture sensingsystem (such as, for example, the mm-wave gesture sensing system 200illustrated in FIG. 2) of the wearable device (such as, for example, thewearable devices 700A, 700B and 700C illustrated in FIGS. 7A, 7B and 7C,respectively) generates a transmitted RF signal. In step 803, a transmitantenna (such as, for example, the transmit antennas 713 a and 713 billustrated in FIGS. 7A, 7B and 7C) transmits the transmitted RF signal(such as, for example, the incident RF signals 717 illustrated in FIGS.7A, 7B and 7C) to a gesturing hand (such as, for example, the gesturinghand 721 illustrated in FIGS. 7A, 7B and 7C) though a portion of thesidewall of the housing (such as, for example, the sidewall 701 s of thehousing 701 illustrated in FIGS. 7A, 7B and 7C) of the wearable device.The transmitted RF signal is transmitted according to a radiationpattern (such as, for example, the radiation patterns 409 or 511illustrated in FIGS. 4B and 5B, respectively). In an embodiment, ahighest gain direction of a main lobe of the radiation patternintersects with the sidewall of the housing of the wearable device, suchthat the transmitted RF signal overlaps with the portion of the sidewallof the housing of the wearable device. In step 805, a receive antenna(such as, for example, the receive antennas 715 a-715 d illustrated inFIGS. 7A, 7B and 7C) receives a reflected RF signal (such as, forexample, the RF signals 719 illustrated in FIGS. 7A, 7B and 7C) from thegesturing hand though the portion of the sidewall of the housing of thewearable device. In step 807, the gesture sensing system detects agesture based on the transmitted RF signal and the reflected RF signal.In an embodiment, the gesture sensing system may compare the reflectedRF signal to the transmitted RF signal to detect the gesture. In step809, the wearable device performs an operation based on the gesture.

Embodiments of the present disclosure are summarized here. Otherembodiments can also be understood form the entirety of thespecification and the claims filed herein. One general aspect includes aradio frequency (RF) system including: an RF integrated circuit (IC)die; an antenna coupled to the RF IC die; and a reflector layer over theRF IC die, the reflector layer extending over at least a portion of theantenna, a combination of the antenna and the reflector layer having aradiation pattern that includes a main lobe in a first directionparallel to a top surface of the reflector layer.

Implementations may include one or more of the following features. TheRF system where the reflector layer includes a metal or a metal alloy.The RF system where the reflector layer is configured to act as a heatsink for the RF IC die. The RF system further including a moldingmaterial encapsulating the RF IC die and the reflector layer. The RFsystem where the antenna is a Yagi-Uda antenna. The RF system where theradiation pattern has a side lobe in a second direction perpendicular tothe first direction. The RF system where the reflector layer isconfigured to redirect an energy of RF signals from the second directionto the first direction.

Another general aspect includes a wearable device including: a housing,the housing having a top portion, a bottom portion, and a sidewallconnecting the top portion to the bottom portion; a circuit board withinthe housing and over the bottom portion of the housing; a radiofrequency (RF) system mounted on the circuit board, the RF systemincluding: an RF integrated circuit (IC) die; an antenna coupled to theRF IC die; and a reflector layer over the RF IC die and the antenna; anda display disposed over the RF system, where a radiation pattern of theRF system has a main lobe in a first direction parallel to a top surfaceof the display, and where the first direction intersects with thesidewall of the housing.

Implementations may include one or more of the following features. Thewearable device where the RF IC die includes radar circuitry coupled tothe antenna. The wearable device further including gesture recognizingprocessing circuitry coupled to the RF IC die. The wearable device wherethe radiation pattern has a side lobe in a second directionperpendicular to the first direction, the second direction intersectingwith the display. The wearable device where a gain of the main lobe isgreater than a gain of the side lobe. The wearable device where the topportion of the housing and the bottom portion of the housing include ametal or a metal alloy. The wearable device where at least a portion ofthe sidewall of the housing is formed of a material transparent formm-wave RF signals. The wearable device where a portion of the sidewallof the housing is not transparent for mm-wave RF signals. The wearabledevice where the reflector layer includes a metal or a metal alloy. Thewearable device where the reflector layer is configured to provide aheat dissipation path from the RF IC die to the top portion of thehousing. The wearable device where the top portion of the housingincludes a high thermal conductivity material. The wearable device wherethe bottom portion of the housing includes a low thermal conductivitymaterial. The wearable device where the wearable device is a smartwatch.

Another general aspect includes a method including: generating, by aradio frequency (RF) system of a wearable device, a transmitted RFsignal; transmitting, by a transmit antenna of the RF system accordingto a radiation pattern, the transmitted RF signal to an object through afirst portion of a sidewall of a housing of the wearable device, where ahighest gain direction of a main lobe of the radiation patternintersects with the first portion of the sidewall of the housing of thewearable device; and receiving, by a receive antenna of the RF system, areflected RF signal from the object through the first portion of thesidewall of the housing of the wearable device.

Implementations may include one or more of the following features. Themethod where the object is a gesturing hand. The method furtherincluding: detecting, by the RF system, a gesture of the gesturing handbased on the transmitted RF signal and the reflected RF signal; andperforming, by the wearable device, an operation based on the gesture.The method where the first portion of the sidewall of the housing of thewearable device includes a first material, where a second portion of thesidewall of the housing of the wearable device includes a secondmaterial different from the first material. The method where the secondportion of the sidewall of the housing of the wearable device is nottransparent for the transmitted RF signal and the reflected RF signal.The method where the first portion of the sidewall of the housing of thewearable device is transparent for the transmitted RF signal and thereflected RF signal. The method where the wearable device is a smartwatch.

While this invention has been described with reference to illustrativeembodiments, this description is not intended to be construed in alimiting sense. Various modifications and combinations of theillustrative embodiments, as well as other embodiments of the invention,will be apparent to persons skilled in the art upon reference to thedescription. It is therefore intended that the appended claims encompassany such modifications or embodiments.

What is claimed is:
 1. A wearable device comprising: a housing, thehousing having a top portion, a bottom portion, and a sidewallconnecting the top portion to the bottom portion; a circuit board withinthe housing and over the bottom portion of the housing; a radiofrequency (RF) system mounted on the circuit board, the RF systemcomprising: an RF integrated circuit (IC) die; an antenna coupled to theRF IC die; and a reflector layer over the RF IC die and the antenna; anda display disposed over the RF system, wherein a radiation pattern ofthe RF system has a main lobe in a first direction parallel to a topsurface of the display, and wherein the first direction intersects withthe sidewall of the housing.
 2. The wearable device of claim 1, whereinthe RF IC die comprises radar circuitry coupled to the antenna.
 3. Thewearable device of claim 2, further comprising gesture recognizingprocessing circuitry coupled to the RF IC die.
 4. The wearable device ofclaim 1, wherein the radiation pattern has a side lobe in a seconddirection perpendicular to the first direction, the second directionintersecting with the display.
 5. The wearable device of claim 4,wherein a gain of the main lobe is greater than a gain of the side lobe.6. The wearable device of claim 1, wherein the top portion of thehousing and the bottom portion of the housing comprise a metal or ametal alloy.
 7. The wearable device of claim 1, wherein at least aportion of the sidewall of the housing is formed of a materialtransparent for mm-wave RF signals.
 8. The wearable device of claim 1,wherein a portion of the sidewall of the housing is not transparent formm-wave RF signals.
 9. The wearable device of claim 1, wherein thereflector layer comprises a metal or a metal alloy.
 10. The wearabledevice of claim 1, wherein the reflector layer is configured to providea heat dissipation path from the RF IC die to the top portion of thehousing.
 11. The wearable device of claim 1, wherein the top portion ofthe housing comprises a high thermal conductivity material.
 12. Thewearable device of claim 1, wherein the bottom portion of the housingcomprises a low thermal conductivity material.
 13. The wearable deviceof claim 1, wherein the wearable device is a smart watch.
 14. A wearabledevice comprising: a housing; a mm-wave gesture sensing system withinthe housing, the mm-wave gesture sensing system comprising a radiofrequency (RF) system, the RF system comprising: an RF integratedcircuit (IC) die; an antenna coupled to the RF IC die; and a reflectorlayer over the RF IC die and the antenna, a combination of the antennaand the reflector layer having a radiation pattern comprising a mainlobe in a first direction parallel to a top surface of the reflectorlayer; and a display disposed over the mm-wave gesture sensing system,wherein the first direction is parallel to a top surface of the display,and wherein the first direction intersects with a sidewall of thehousing.
 15. The wearable device of claim 14, wherein the reflectorlayer comprises a metal or a metal alloy.
 16. The wearable device ofclaim 14, wherein the reflector layer is configured to act as a heatsink for the RF IC die.
 17. The wearable device of claim 14, wherein theRF system further comprises a molding material encapsulating the RF ICdie and the reflector layer.
 18. The wearable device of claim 14,wherein the antenna is a Yagi-Uda antenna.
 19. The wearable device ofclaim 14, wherein the radiation pattern has a side lobe in a seconddirection perpendicular to the first direction.
 20. The wearable deviceof claim 19, wherein the reflector layer is configured to redirect anenergy of RF signals from the second direction to the first direction.21. A wearable device comprising: a housing, the housing having a topportion, a bottom portion, and a sidewall portion extending between thetop portion and the bottom portion; a circuit board between the topportion and the bottom portion of the housing; a mm-wave gesture sensingsystem mounted on the circuit board, the mm-wave gesture sensing systemcomprising a radio frequency (RF) system, the RF system comprising: anRF integrated circuit (IC) die; an antenna coupled to the RF IC die; anda reflector layer over the RF IC die, the reflector layer extending overat least a portion of the antenna, wherein a highest gain direction of amain lobe of a radiation pattern of the RF system intersects with thesidewall portion of the housing; and a display disposed over the RFsystem, wherein the highest gain direction of the main lobe of theradiation pattern of the RF system is parallel to a top surface of thedisplay.
 22. The wearable device of claim 21, wherein a portion of thesidewall portion of the housing intersecting with the highest gaindirection comprises a material transparent for mm-wave RF signals. 23.The wearable device of claim 21, wherein the reflector layer comprises ahigh thermal conductivity material.
 24. The wearable device of claim 21,wherein the antenna is a directional antenna.
 25. The wearable device ofclaim 21, wherein the RF system further comprises a molding materialencapsulating the RF IC die, the antenna and the reflector layer. 26.The wearable device of claim 21, wherein the top portion of the housingcomprises a metallic material.
 27. The wearable device of claim 21,wherein the bottom portion of the housing comprises a low thermalconductivity material.